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My first initial commit with all of mine experimental changes.

Dmitry Kabak (userdima committed 13 years ago

Commit d37b88d1 parent 3f5b46618352 files · +2598093 −-8690Browse files

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1+/*
2+ * Copyright (c) 1994, 2010, Oracle and/or its affiliates. All rights reserved.
3+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4+ *
5+ * This code is free software; you can redistribute it and/or modify it
6+ * under the terms of the GNU General Public License version 2 only, as
7+ * published by the Free Software Foundation. Oracle designates this
8+ * particular file as subject to the "Classpath" exception as provided
9+ * by Oracle in the LICENSE file that accompanied this code.
10+ *
11+ * This code is distributed in the hope that it will be useful, but WITHOUT
12+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14+ * version 2 for more details (a copy is included in the LICENSE file that
15+ * accompanied this code).
16+ *
17+ * You should have received a copy of the GNU General Public License version
18+ * 2 along with this work; if not, write to the Free Software Foundation,
19+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20+ *
21+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22+ * or visit www.oracle.com if you need additional information or have any
23+ * questions.
24+ */
25+
26+package java.lang;
27+
28+/**
29+ * Class {@code Object} is the root of the class hierarchy.
30+ * Every class has {@code Object} as a superclass. All objects,
31+ * including arrays, implement the methods of this class.
32+ *
33+ * @author unascribed
34+ * @see java.lang.Class
35+ * @since JDK1.0
36+ */
37+public class Object {
38+
39+ private static native void registerNatives();
40+ static {
41+ registerNatives();
42+ }
43+
44+ /**
45+ * Returns the runtime class of this {@code Object}. The returned
46+ * {@code Class} object is the object that is locked by {@code
47+ * static synchronized} methods of the represented class.
48+ *
49+ * <p><b>The actual result type is {@code Class<? extends |X|>}
50+ * where {@code |X|} is the erasure of the static type of the
51+ * expression on which {@code getClass} is called.</b> For
52+ * example, no cast is required in this code fragment:</p>
53+ *
54+ * <p>
55+ * {@code Number n = 0; }<br>
56+ * {@code Class<? extends Number> c = n.getClass(); }
57+ * </p>
58+ *
59+ * @return The {@code Class} object that represents the runtime
60+ * class of this object.
61+ * @see Class Literals, section 15.8.2 of
62+ * <cite>The Java&trade; Language Specification</cite>.
63+ */
64+ public final native Class<?> getClass();
65+
66+ /**
67+ * Returns a hash code value for the object. This method is
68+ * supported for the benefit of hash tables such as those provided by
69+ * {@link java.util.HashMap}.
70+ * <p>
71+ * The general contract of {@code hashCode} is:
72+ * <ul>
73+ * <li>Whenever it is invoked on the same object more than once during
74+ * an execution of a Java application, the {@code hashCode} method
75+ * must consistently return the same integer, provided no information
76+ * used in {@code equals} comparisons on the object is modified.
77+ * This integer need not remain consistent from one execution of an
78+ * application to another execution of the same application.
79+ * <li>If two objects are equal according to the {@code equals(Object)}
80+ * method, then calling the {@code hashCode} method on each of
81+ * the two objects must produce the same integer result.
82+ * <li>It is <em>not</em> required that if two objects are unequal
83+ * according to the {@link java.lang.Object#equals(java.lang.Object)}
84+ * method, then calling the {@code hashCode} method on each of the
85+ * two objects must produce distinct integer results. However, the
86+ * programmer should be aware that producing distinct integer results
87+ * for unequal objects may improve the performance of hash tables.
88+ * </ul>
89+ * <p>
90+ * As much as is reasonably practical, the hashCode method defined by
91+ * class {@code Object} does return distinct integers for distinct
92+ * objects. (This is typically implemented by converting the internal
93+ * address of the object into an integer, but this implementation
94+ * technique is not required by the
95+ * Java<font size="-2"><sup>TM</sup></font> programming language.)
96+ *
97+ * @return a hash code value for this object.
98+ * @see java.lang.Object#equals(java.lang.Object)
99+ * @see java.lang.System#identityHashCode
100+ */
101+ public native int hashCode();
102+
103+ /**
104+ * Indicates whether some other object is "equal to" this one.
105+ * <p>
106+ * The {@code equals} method implements an equivalence relation
107+ * on non-null object references:
108+ * <ul>
109+ * <li>It is <i>reflexive</i>: for any non-null reference value
110+ * {@code x}, {@code x.equals(x)} should return
111+ * {@code true}.
112+ * <li>It is <i>symmetric</i>: for any non-null reference values
113+ * {@code x} and {@code y}, {@code x.equals(y)}
114+ * should return {@code true} if and only if
115+ * {@code y.equals(x)} returns {@code true}.
116+ * <li>It is <i>transitive</i>: for any non-null reference values
117+ * {@code x}, {@code y}, and {@code z}, if
118+ * {@code x.equals(y)} returns {@code true} and
119+ * {@code y.equals(z)} returns {@code true}, then
120+ * {@code x.equals(z)} should return {@code true}.
121+ * <li>It is <i>consistent</i>: for any non-null reference values
122+ * {@code x} and {@code y}, multiple invocations of
123+ * {@code x.equals(y)} consistently return {@code true}
124+ * or consistently return {@code false}, provided no
125+ * information used in {@code equals} comparisons on the
126+ * objects is modified.
127+ * <li>For any non-null reference value {@code x},
128+ * {@code x.equals(null)} should return {@code false}.
129+ * </ul>
130+ * <p>
131+ * The {@code equals} method for class {@code Object} implements
132+ * the most discriminating possible equivalence relation on objects;
133+ * that is, for any non-null reference values {@code x} and
134+ * {@code y}, this method returns {@code true} if and only
135+ * if {@code x} and {@code y} refer to the same object
136+ * ({@code x == y} has the value {@code true}).
137+ * <p>
138+ * Note that it is generally necessary to override the {@code hashCode}
139+ * method whenever this method is overridden, so as to maintain the
140+ * general contract for the {@code hashCode} method, which states
141+ * that equal objects must have equal hash codes.
142+ *
143+ * @param obj the reference object with which to compare.
144+ * @return {@code true} if this object is the same as the obj
145+ * argument; {@code false} otherwise.
146+ * @see #hashCode()
147+ * @see java.util.HashMap
148+ */
149+ public boolean equals(Object obj) {
150+ return (this == obj);
151+ }
152+
153+ /**
154+ * Creates and returns a copy of this object. The precise meaning
155+ * of "copy" may depend on the class of the object. The general
156+ * intent is that, for any object {@code x}, the expression:
157+ * <blockquote>
158+ * <pre>
159+ * x.clone() != x</pre></blockquote>
160+ * will be true, and that the expression:
161+ * <blockquote>
162+ * <pre>
163+ * x.clone().getClass() == x.getClass()</pre></blockquote>
164+ * will be {@code true}, but these are not absolute requirements.
165+ * While it is typically the case that:
166+ * <blockquote>
167+ * <pre>
168+ * x.clone().equals(x)</pre></blockquote>
169+ * will be {@code true}, this is not an absolute requirement.
170+ * <p>
171+ * By convention, the returned object should be obtained by calling
172+ * {@code super.clone}. If a class and all of its superclasses (except
173+ * {@code Object}) obey this convention, it will be the case that
174+ * {@code x.clone().getClass() == x.getClass()}.
175+ * <p>
176+ * By convention, the object returned by this method should be independent
177+ * of this object (which is being cloned). To achieve this independence,
178+ * it may be necessary to modify one or more fields of the object returned
179+ * by {@code super.clone} before returning it. Typically, this means
180+ * copying any mutable objects that comprise the internal "deep structure"
181+ * of the object being cloned and replacing the references to these
182+ * objects with references to the copies. If a class contains only
183+ * primitive fields or references to immutable objects, then it is usually
184+ * the case that no fields in the object returned by {@code super.clone}
185+ * need to be modified.
186+ * <p>
187+ * The method {@code clone} for class {@code Object} performs a
188+ * specific cloning operation. First, if the class of this object does
189+ * not implement the interface {@code Cloneable}, then a
190+ * {@code CloneNotSupportedException} is thrown. Note that all arrays
191+ * are considered to implement the interface {@code Cloneable} and that
192+ * the return type of the {@code clone} method of an array type {@code T[]}
193+ * is {@code T[]} where T is any reference or primitive type.
194+ * Otherwise, this method creates a new instance of the class of this
195+ * object and initializes all its fields with exactly the contents of
196+ * the corresponding fields of this object, as if by assignment; the
197+ * contents of the fields are not themselves cloned. Thus, this method
198+ * performs a "shallow copy" of this object, not a "deep copy" operation.
199+ * <p>
200+ * The class {@code Object} does not itself implement the interface
201+ * {@code Cloneable}, so calling the {@code clone} method on an object
202+ * whose class is {@code Object} will result in throwing an
203+ * exception at run time.
204+ *
205+ * @return a clone of this instance.
206+ * @exception CloneNotSupportedException if the object's class does not
207+ * support the {@code Cloneable} interface. Subclasses
208+ * that override the {@code clone} method can also
209+ * throw this exception to indicate that an instance cannot
210+ * be cloned.
211+ * @see java.lang.Cloneable
212+ */
213+ protected native Object clone() throws CloneNotSupportedException;
214+
215+ /**
216+ * Returns a string representation of the object. In general, the
217+ * {@code toString} method returns a string that
218+ * "textually represents" this object. The result should
219+ * be a concise but informative representation that is easy for a
220+ * person to read.
221+ * It is recommended that all subclasses override this method.
222+ * <p>
223+ * The {@code toString} method for class {@code Object}
224+ * returns a string consisting of the name of the class of which the
225+ * object is an instance, the at-sign character `{@code @}', and
226+ * the unsigned hexadecimal representation of the hash code of the
227+ * object. In other words, this method returns a string equal to the
228+ * value of:
229+ * <blockquote>
230+ * <pre>
231+ * getClass().getName() + '@' + Integer.toHexString(hashCode())
232+ * </pre></blockquote>
233+ *
234+ * @return a string representation of the object.
235+ */
236+ public String toString() {
237+ return getClass().getName() + "@" + Integer.toHexString(hashCode());
238+ }
239+
240+ /**
241+ * Wakes up a single thread that is waiting on this object's
242+ * monitor. If any threads are waiting on this object, one of them
243+ * is chosen to be awakened. The choice is arbitrary and occurs at
244+ * the discretion of the implementation. A thread waits on an object's
245+ * monitor by calling one of the {@code wait} methods.
246+ * <p>
247+ * The awakened thread will not be able to proceed until the current
248+ * thread relinquishes the lock on this object. The awakened thread will
249+ * compete in the usual manner with any other threads that might be
250+ * actively competing to synchronize on this object; for example, the
251+ * awakened thread enjoys no reliable privilege or disadvantage in being
252+ * the next thread to lock this object.
253+ * <p>
254+ * This method should only be called by a thread that is the owner
255+ * of this object's monitor. A thread becomes the owner of the
256+ * object's monitor in one of three ways:
257+ * <ul>
258+ * <li>By executing a synchronized instance method of that object.
259+ * <li>By executing the body of a {@code synchronized} statement
260+ * that synchronizes on the object.
261+ * <li>For objects of type {@code Class,} by executing a
262+ * synchronized static method of that class.
263+ * </ul>
264+ * <p>
265+ * Only one thread at a time can own an object's monitor.
266+ *
267+ * @exception IllegalMonitorStateException if the current thread is not
268+ * the owner of this object's monitor.
269+ * @see java.lang.Object#notifyAll()
270+ * @see java.lang.Object#wait()
271+ */
272+ public final native void notify();
273+
274+ /**
275+ * Wakes up all threads that are waiting on this object's monitor. A
276+ * thread waits on an object's monitor by calling one of the
277+ * {@code wait} methods.
278+ * <p>
279+ * The awakened threads will not be able to proceed until the current
280+ * thread relinquishes the lock on this object. The awakened threads
281+ * will compete in the usual manner with any other threads that might
282+ * be actively competing to synchronize on this object; for example,
283+ * the awakened threads enjoy no reliable privilege or disadvantage in
284+ * being the next thread to lock this object.
285+ * <p>
286+ * This method should only be called by a thread that is the owner
287+ * of this object's monitor. See the {@code notify} method for a
288+ * description of the ways in which a thread can become the owner of
289+ * a monitor.
290+ *
291+ * @exception IllegalMonitorStateException if the current thread is not
292+ * the owner of this object's monitor.
293+ * @see java.lang.Object#notify()
294+ * @see java.lang.Object#wait()
295+ */
296+ public final native void notifyAll();
297+
298+ /**
299+ * Causes the current thread to wait until either another thread invokes the
300+ * {@link java.lang.Object#notify()} method or the
301+ * {@link java.lang.Object#notifyAll()} method for this object, or a
302+ * specified amount of time has elapsed.
303+ * <p>
304+ * The current thread must own this object's monitor.
305+ * <p>
306+ * This method causes the current thread (call it <var>T</var>) to
307+ * place itself in the wait set for this object and then to relinquish
308+ * any and all synchronization claims on this object. Thread <var>T</var>
309+ * becomes disabled for thread scheduling purposes and lies dormant
310+ * until one of four things happens:
311+ * <ul>
312+ * <li>Some other thread invokes the {@code notify} method for this
313+ * object and thread <var>T</var> happens to be arbitrarily chosen as
314+ * the thread to be awakened.
315+ * <li>Some other thread invokes the {@code notifyAll} method for this
316+ * object.
317+ * <li>Some other thread {@linkplain Thread#interrupt() interrupts}
318+ * thread <var>T</var>.
319+ * <li>The specified amount of real time has elapsed, more or less. If
320+ * {@code timeout} is zero, however, then real time is not taken into
321+ * consideration and the thread simply waits until notified.
322+ * </ul>
323+ * The thread <var>T</var> is then removed from the wait set for this
324+ * object and re-enabled for thread scheduling. It then competes in the
325+ * usual manner with other threads for the right to synchronize on the
326+ * object; once it has gained control of the object, all its
327+ * synchronization claims on the object are restored to the status quo
328+ * ante - that is, to the situation as of the time that the {@code wait}
329+ * method was invoked. Thread <var>T</var> then returns from the
330+ * invocation of the {@code wait} method. Thus, on return from the
331+ * {@code wait} method, the synchronization state of the object and of
332+ * thread {@code T} is exactly as it was when the {@code wait} method
333+ * was invoked.
334+ * <p>
335+ * A thread can also wake up without being notified, interrupted, or
336+ * timing out, a so-called <i>spurious wakeup</i>. While this will rarely
337+ * occur in practice, applications must guard against it by testing for
338+ * the condition that should have caused the thread to be awakened, and
339+ * continuing to wait if the condition is not satisfied. In other words,
340+ * waits should always occur in loops, like this one:
341+ * <pre>
342+ * synchronized (obj) {
343+ * while (&lt;condition does not hold&gt;)
344+ * obj.wait(timeout);
345+ * ... // Perform action appropriate to condition
346+ * }
347+ * </pre>
348+ * (For more information on this topic, see Section 3.2.3 in Doug Lea's
349+ * "Concurrent Programming in Java (Second Edition)" (Addison-Wesley,
350+ * 2000), or Item 50 in Joshua Bloch's "Effective Java Programming
351+ * Language Guide" (Addison-Wesley, 2001).
352+ *
353+ * <p>If the current thread is {@linkplain java.lang.Thread#interrupt()
354+ * interrupted} by any thread before or while it is waiting, then an
355+ * {@code InterruptedException} is thrown. This exception is not
356+ * thrown until the lock status of this object has been restored as
357+ * described above.
358+ *
359+ * <p>
360+ * Note that the {@code wait} method, as it places the current thread
361+ * into the wait set for this object, unlocks only this object; any
362+ * other objects on which the current thread may be synchronized remain
363+ * locked while the thread waits.
364+ * <p>
365+ * This method should only be called by a thread that is the owner
366+ * of this object's monitor. See the {@code notify} method for a
367+ * description of the ways in which a thread can become the owner of
368+ * a monitor.
369+ *
370+ * @param timeout the maximum time to wait in milliseconds.
371+ * @exception IllegalArgumentException if the value of timeout is
372+ * negative.
373+ * @exception IllegalMonitorStateException if the current thread is not
374+ * the owner of the object's monitor.
375+ * @exception InterruptedException if any thread interrupted the
376+ * current thread before or while the current thread
377+ * was waiting for a notification. The <i>interrupted
378+ * status</i> of the current thread is cleared when
379+ * this exception is thrown.
380+ * @see java.lang.Object#notify()
381+ * @see java.lang.Object#notifyAll()
382+ */
383+ public final native void wait(long timeout) throws InterruptedException;
384+
385+ /**
386+ * Causes the current thread to wait until another thread invokes the
387+ * {@link java.lang.Object#notify()} method or the
388+ * {@link java.lang.Object#notifyAll()} method for this object, or
389+ * some other thread interrupts the current thread, or a certain
390+ * amount of real time has elapsed.
391+ * <p>
392+ * This method is similar to the {@code wait} method of one
393+ * argument, but it allows finer control over the amount of time to
394+ * wait for a notification before giving up. The amount of real time,
395+ * measured in nanoseconds, is given by:
396+ * <blockquote>
397+ * <pre>
398+ * 1000000*timeout+nanos</pre></blockquote>
399+ * <p>
400+ * In all other respects, this method does the same thing as the
401+ * method {@link #wait(long)} of one argument. In particular,
402+ * {@code wait(0, 0)} means the same thing as {@code wait(0)}.
403+ * <p>
404+ * The current thread must own this object's monitor. The thread
405+ * releases ownership of this monitor and waits until either of the
406+ * following two conditions has occurred:
407+ * <ul>
408+ * <li>Another thread notifies threads waiting on this object's monitor
409+ * to wake up either through a call to the {@code notify} method
410+ * or the {@code notifyAll} method.
411+ * <li>The timeout period, specified by {@code timeout}
412+ * milliseconds plus {@code nanos} nanoseconds arguments, has
413+ * elapsed.
414+ * </ul>
415+ * <p>
416+ * The thread then waits until it can re-obtain ownership of the
417+ * monitor and resumes execution.
418+ * <p>
419+ * As in the one argument version, interrupts and spurious wakeups are
420+ * possible, and this method should always be used in a loop:
421+ * <pre>
422+ * synchronized (obj) {
423+ * while (&lt;condition does not hold&gt;)
424+ * obj.wait(timeout, nanos);
425+ * ... // Perform action appropriate to condition
426+ * }
427+ * </pre>
428+ * This method should only be called by a thread that is the owner
429+ * of this object's monitor. See the {@code notify} method for a
430+ * description of the ways in which a thread can become the owner of
431+ * a monitor.
432+ *
433+ * @param timeout the maximum time to wait in milliseconds.
434+ * @param nanos additional time, in nanoseconds range
435+ * 0-999999.
436+ * @exception IllegalArgumentException if the value of timeout is
437+ * negative or the value of nanos is
438+ * not in the range 0-999999.
439+ * @exception IllegalMonitorStateException if the current thread is not
440+ * the owner of this object's monitor.
441+ * @exception InterruptedException if any thread interrupted the
442+ * current thread before or while the current thread
443+ * was waiting for a notification. The <i>interrupted
444+ * status</i> of the current thread is cleared when
445+ * this exception is thrown.
446+ */
447+ public final void wait(long timeout, int nanos) throws InterruptedException {
448+ if (timeout < 0) {
449+ throw new IllegalArgumentException("timeout value is negative");
450+ }
451+
452+ if (nanos < 0 || nanos > 999999) {
453+ throw new IllegalArgumentException(
454+ "nanosecond timeout value out of range");
455+ }
456+
457+ if (nanos >= 500000 || (nanos != 0 && timeout == 0)) {
458+ timeout++;
459+ }
460+
461+ wait(timeout);
462+ }
463+
464+ /**
465+ * Causes the current thread to wait until another thread invokes the
466+ * {@link java.lang.Object#notify()} method or the
467+ * {@link java.lang.Object#notifyAll()} method for this object.
468+ * In other words, this method behaves exactly as if it simply
469+ * performs the call {@code wait(0)}.
470+ * <p>
471+ * The current thread must own this object's monitor. The thread
472+ * releases ownership of this monitor and waits until another thread
473+ * notifies threads waiting on this object's monitor to wake up
474+ * either through a call to the {@code notify} method or the
475+ * {@code notifyAll} method. The thread then waits until it can
476+ * re-obtain ownership of the monitor and resumes execution.
477+ * <p>
478+ * As in the one argument version, interrupts and spurious wakeups are
479+ * possible, and this method should always be used in a loop:
480+ * <pre>
481+ * synchronized (obj) {
482+ * while (&lt;condition does not hold&gt;)
483+ * obj.wait();
484+ * ... // Perform action appropriate to condition
485+ * }
486+ * </pre>
487+ * This method should only be called by a thread that is the owner
488+ * of this object's monitor. See the {@code notify} method for a
489+ * description of the ways in which a thread can become the owner of
490+ * a monitor.
491+ *
492+ * @exception IllegalMonitorStateException if the current thread is not
493+ * the owner of the object's monitor.
494+ * @exception InterruptedException if any thread interrupted the
495+ * current thread before or while the current thread
496+ * was waiting for a notification. The <i>interrupted
497+ * status</i> of the current thread is cleared when
498+ * this exception is thrown.
499+ * @see java.lang.Object#notify()
500+ * @see java.lang.Object#notifyAll()
501+ */
502+ public final void wait() throws InterruptedException {
503+ wait(0);
504+ }
505+
506+ /**
507+ * Called by the garbage collector on an object when garbage collection
508+ * determines that there are no more references to the object.
509+ * A subclass overrides the {@code finalize} method to dispose of
510+ * system resources or to perform other cleanup.
511+ * <p>
512+ * The general contract of {@code finalize} is that it is invoked
513+ * if and when the Java<font size="-2"><sup>TM</sup></font> virtual
514+ * machine has determined that there is no longer any
515+ * means by which this object can be accessed by any thread that has
516+ * not yet died, except as a result of an action taken by the
517+ * finalization of some other object or class which is ready to be
518+ * finalized. The {@code finalize} method may take any action, including
519+ * making this object available again to other threads; the usual purpose
520+ * of {@code finalize}, however, is to perform cleanup actions before
521+ * the object is irrevocably discarded. For example, the finalize method
522+ * for an object that represents an input/output connection might perform
523+ * explicit I/O transactions to break the connection before the object is
524+ * permanently discarded.
525+ * <p>
526+ * The {@code finalize} method of class {@code Object} performs no
527+ * special action; it simply returns normally. Subclasses of
528+ * {@code Object} may override this definition.
529+ * <p>
530+ * The Java programming language does not guarantee which thread will
531+ * invoke the {@code finalize} method for any given object. It is
532+ * guaranteed, however, that the thread that invokes finalize will not
533+ * be holding any user-visible synchronization locks when finalize is
534+ * invoked. If an uncaught exception is thrown by the finalize method,
535+ * the exception is ignored and finalization of that object terminates.
536+ * <p>
537+ * After the {@code finalize} method has been invoked for an object, no
538+ * further action is taken until the Java virtual machine has again
539+ * determined that there is no longer any means by which this object can
540+ * be accessed by any thread that has not yet died, including possible
541+ * actions by other objects or classes which are ready to be finalized,
542+ * at which point the object may be discarded.
543+ * <p>
544+ * The {@code finalize} method is never invoked more than once by a Java
545+ * virtual machine for any given object.
546+ * <p>
547+ * Any exception thrown by the {@code finalize} method causes
548+ * the finalization of this object to be halted, but is otherwise
549+ * ignored.
550+ *
551+ * @throws Throwable the {@code Exception} raised by this method
552+ */
553+ protected void finalize() throws Throwable { }
554+}